1. Field of the Invention
This invention relates to an apparatus for enabling the operation of a conventional gasoline engine by an auxiliary fuel source such as liquefied propane gas.
2. Discussion of Related Art
The increasingly high cost of conventional gasoline fuels and the increating incidence of low availability of the gasoline leading to long gas lines and short tempers has produced a need for a means of using an auxiliary fuel in a conventional gasoline vehicle.
Furthermore, in view of the high pollution consciousness of society, it is desirable to provide a means of fueling a conventional internal combustion engine which is capable of reducing exhaust gas pollutants to a minimum.
U.S. Pat. No. 3,184,295, issued May 18, 1965 to Baverstock, shows an LPG fuel system for internal combustion engines which includes a vaporizer having a heated metal base member with an inlet for liquid and an outlet for gas. The system utilizes an engine manifold vacuum sensor to control gas pressure. When the vacuum falls below a predetermined level, the regulator pressure is increased. U.S. Pat. No. 3,718,000, issued Feb. 27, 1973 to Walker, shows a dual fuel motor using liquid fuel such as gasoline and a gaseous fuel such as LPG. The Walker system includes exhaust treating devices in the exhaust system that operate efficiently when above a predetermined temperature. A thermally sensitive control change-over from gas to gasoline is effected when the treater reaches a desired temperature and switches back to gas fuel when below a desired temperature. U.S. Pat. No. 3,982,516, issued Sept. 28, 1976 to Abernathy, shows a standby system to provide a gaseous fuel to an internal combustion engine in the event of the failure of a primary source of fuel. The Abernathy system includes a primary source of fuel and a standby source of fuel and a normally open pressure switch which is responsive to a predetermined lower-than-normal pressure in a primary source of fuel to indicate a failure thereof. A vacuum sensor is responsive to engine vacuum and communicates the standby source of fuel to the engine fuel-air mixer when the primary source fails and fuel is demanded by the engine.
While various types of systems have heretofore been provided, as for example those discussed above, for providing auxiliary fuel sources or reduced emissions engine operation, considerable operating problems have been encountered with their use. Also, considerable expense is involved in adapting an existing engine to utilize these systems.